Method of cane-sugar production



To all whom itmayio omern: l Be it known that we, HOWARD S. PAINE,,.'

Patented Feb. 9', 1926.

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WASHINGTON, DIsTnIcT or coLUMBIA, ANn VICTOR IBIRCKNER, or: .oxo HILL, MARYLAND, DEDICATED, .BY MESNE ASSIGNMENTS, To-THE cITIzn'Ns or THE UNITED sTATns or AMnnIcA;

METHOD or CAhl'E SUGAR rncDucTI'oN,

No Drawing.

Application filed February a, 1924. serial No. Gaines.

(GRANTED uNnan Tan AcTor xenon 3,1383; east-A L. 625).

Gumtree F. WALTO Jr, and VICTOR BmcKNER, citizens. of the United States of America, and employees of the Department of Agriculture of the United States, resid- Maryland, Washington, 1

ing at Chevy'Chase, District of Columbia, and Oxon H11l,'Maryland, respectively, have jointly invented new and useful tion. p

This application is made under the act of March 3, 1883, chapter143 (22 Stat. 625) Methods of Cane-Sugar Producand the invention herein described and claimed may be used by the Government of the United States or any of its oflicers or employees in' the prosecution of work for the Government, or' by any citizen of the United States, without.

I payment 'to us of any royalty thereon.

Our invention relates particularly to the: desugarization of cane molasses, and applies also to the recovery of sucrose from other products containing sucrose together with other sugars. 'Desugarization of beet molasses has long been an established commercial practice, but when the same procedures have. been applied to exhausted sugar cane molasses, that is, cane molasses from which all sucrose possible has been recovered .by-

direct crystalli'zatiomthe results have not been sufli'cintly satisfactory to justify the adoption of the process on a commercial scale. 'llie diiference in results obtained when working withbeet molasses, and those fouudwhen applying the same. methods to cane molasses, seems to be attributable to their diiference in composition. Beet mo-- lasses contains practically no dextroseand levulose, whereas exhausted cane molasses does contain a large percentage of these sugars. Very good evidence has beenobtained that dextrose and levulose, and also the decomposition products of these sugars, interfere with the production of saccharate of suitable composition when attempting to desugarize sugar cane molasses.

It has been known for some time that by selective fermentation of such sugars as dextrose and levulose, making use of microorganisms substantially free from invertase,

'fermentable. without the aid princi move here of the process as ordinarily 'to the liquor resulting from the se fermentatlon of sugar cane molasses. Ethyl.

" is possible to first for"errample those of the pseudosaccharomyces apiculatus' group, sugars that are of invertase, for

example dextrose and levulose,, canbe decomposed .and -thereb I eliminated.v from 1 sugarcane imolasses, eavin' the sucrose practically intact. It was rst proposed v(U. S. Patent"?51,990) to make'use of this 1c of selective fermentation; to .re-- extrose and levulose, employing mfem.--

seudosaccharomyces apiculatus group, and ollowing the com letion of the fermentation to concentrate t e fermented liquor containin sucrose in a-vacuum' pan according. to t e customary sugar-house practice to obtain sucrose lization.

More recently (US. Patent 1,401,433) to combine the' idea by direct crystalan attempt has been 'inadeof selective fermentation of dextrose and levulose with a modification of the saccharate ization ofbeet molasses. v v

We have found thatf it-is not necessary to make "use of any ethylalcohol in -connecp ed to the'.desuga tion'with the sacc arate process as applied ective alcohol is produce during fermentation, but

this may berecovered before the application of the saccharate manner recommended.

process, if desired, or-it make the saccharate. and

subsequently, recover the products" of, fermentation. At all events. it is not necessary to may use of added 'ethyl alcohol in theasv .In our process we have employed suitable members of the pseudos'aceharomyces apiculatus oup which are substantially free from mvertase, and have fe'rmentedgthedextrose and levulose, leaving the sucrose virtually intact. After the fermentation has been completed, we have been successful in tpreparing saccharate of suitable quality wi out the necessity for using any added amount of ethyl alcohol. -We have been successful in applying the well-known and established Steffen process for the formation of saccharate of lime, Without. substantial modifications. It follows, therefore, that the saccharates of barium, lead, strontium.-

' as applied in members of the S. apiculatus group.

Following the manufacture of saccharate of lime in our process, the saccharate is decomposed by carbon dioxide and the calcium carbonateseparated from the sugar liquor,

-which isthen evaporated in a vacuum pan in the customary manner to obtain sucrose by crystallization. This rocedure does not differ from well-known 1ndustrial practice the recovery of sucrose from beet molasses, and is not claimed as a part of our invention.

The selective fermentation of dextrose and levulose produces ethyl alcohol, which in our process may be recovered either before or after the precipitation of saccharate. The best results have been obtained when saccharate has been made first and the ethyl alcohol recovered subsequentlyl The following details of our process are givenas an example of the procedure developed, although the conditions of time, temperature, density and quantity of liquors and reagents, etc., may bevaried in the application ofour process to meet varying commercial conditions.

The molasses is diluted to a density of 18 Brix and subjected to pure culture selective fermentation of invert sugar by suitalie t the end of the fermentation period, the length of which will depend upon the size and vigor of the starter employed as well as on other conditions, but which has been found to require approximately 4 days, the invert sugar is very nearly completely fer- Inented without substantial loss of sucrose, the ratio of invert sugar to sucrose after fermentation being approximately 1 to 6.5. .The sucrose content of the fermented liquor is about 5 per cent, which is considered a satisfactory concentration, without either dilution or evaporation, for the next stage inthe process, which is the production of calcium saccharate.

Employing an experimental Stefien cooler of the same design as is commonly used on a lar e scale in the beet sugar industry, a

charge of 14 liters of the fermented 1i uor containing 5 per cent sucrose was ta en.

- After. cooling to a temperature of 10 C.

' powdered lime portion of 1 (0210) was-added in the prollme to 1 sucrose, the lime being slowly and automatically added over a period of fifteen minutes- The cold saccharate cake resulting after filtration was 'washed with ten liters of water at a temperature of 15- C. and dried by vacuum. cake was then suspended in water to a density of about 35 Brix, heated to 85 C. and carbonated to neutrality to phenolphthalein. 'l he precipitated calcium carbonate was subhot saccharate 1s ready for s'equently washed with a of hot' water to reduce its sucrose content to roughly 0.5 per cent. The products ofthe initial fermentation now contained in the combined filtrate, or waste, and the wash from the cold saccharate filtration were next obtained by distillation. Finally the residue was heated to a temperature of 85 C. for fifteen minutes to produce the maximum yield of hot saccharate, which was then filtered off. and washed with a minimum of hot water to reduce the impurities contained therein without substantial lossof sucrose. If suflicient heat has been applied during distillation, the

ltra'tion without additional heat treatment.

In a cycle of five experiments, making saccharate as above descr1bed, a certain proportion of the hot saccharate resulting from the first experiment in the cycle was used to make a preliminary clarification of the fermented liquor to be subjected to the cold saccharate operation for the second experiment in the cycle, and similarly a proportion of the hot saccharate from the second experiment was employed to clarify the liquor prepared for the third experiment in the cycle, etc. The quantity of hot saccharate employed for this purpose was equivalent to 5 per cent of powdered lime (CaO) based on the sucrose content of the fermented liquor. The remainder of the. hot saccharate was added directly to the cooler, where it was combined with the clarified liquor, this procedure being systematically followed throughout the cycle of the five experiments. The averagemf the true purities (ratio of sucrose to total solids) of the five cold saccharate'liquors was 80.6. .The average Brix was 8.0 and the total recovery of sucrose 76.96 per cent.

We claim:

1. The process of recovering sucrose from molasses, which consists of the removal of the invert sugar contained in the molasses, by selective fermentation, the precipitation of the residual sucrose as saccharate, the de composition of the saccharate to obtain sucrose in solution, filtration of the sucrose solution and the subsequent crystallization of sucrose.

2. The process of recovering sucrose from molasses, which consists of the removal of the invert sugar contained in the molasses by selective fermentation, the precipitation of theresidual sucroseas saccharate by the addition of lime, the decomposition of the calcium saccharate by the use of carbon dioxide to obtain sucrose in solution, filtration of the sucrose solution to remove the carbonate of lime, and the subsequent crystallization of sucrose. 

